Grenfell Tower

the_killjoy

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I was surprised to see most flats don't have fire doors to the corridors. Of course you cannot just replace the current one as fire doors cannot have letterboxes ...
 

flecc

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I was surprised to see most flats don't have fire doors to the corridors. Of course you cannot just replace the current one as fire doors cannot have letterboxes ...
The regulations have always seemed odd in this respect. I moved into my flat when it was newly built and as with all the other flats, alongside the front door and high up there was a large airbrick into the common hallway. The fire brigade came round on an inspection a month or so later and immediately ruled that they had to be removed and the wall made good, which the builders quickly did.

We do have fire resistant front doors with an intermediate steel plate sandwiched in, and I can easily believe the doors live up to the claimed 30 minutes minimum fire resistance time. The lease doesn't permit a cat flap to be cut in or the doors changed to an unapproved type.

However they all have a letterbox at mid level. There's a plastic letterbox flap inside and a heavy aluminium one on the outside of the door which would delay fire transfer, but not stop it.

So all very odd, airbricks and catflaps are not ok, but a letterbox is!
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Croxden

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A good rhyme that.
 

Danidl

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The regulations have always seemed odd in this respect. I moved into my flat when it was newly built and as with all the other flats, alongside the front door and high up there was a large airbrick into the common hallway. The fire brigade came round on an inspection a month or so later and immediately ruled that they had to be removed and the wall made good, which the builders quickly did.

We do have fire resistant front doors with an intermediate steel plate sandwiched in, and I can easily believe the doors live up to the claimed 30 minutes minimum fire resistance time. The lease doesn't permit a cat flap to be cut in or the doors changed to an unapproved type.

However they all have a letterbox at mid level. There's a plastic letterbox flap inside and a heavy aluminium one on the outside of the door which would delay fire transfer, but not stop it.

So all very odd, airbricks and catflaps are not ok, but a letterbox is!
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Neither the airbrick or the catflap will be smoke tight, the metal letter flap will be. The aperture for the letter flap should be much smaller than a catflap.
 

flecc

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Neither the airbrick or the catflap will be smoke tight, the metal letter flap will be. The aperture for the letter flap should be much smaller than a catflap.
Unfortunately that's where the letterbox falls down. It's a monster, 26cm wide by 6cm deep aperture, all sorts of large stuff can be posted though it. Useful though, since I often get packages delivered through it Someone installed a cat flap in the outer porch window years ago and I've just checked the aperture areas. The cat flap 168 sq. cm, the letterbox 156 sq. cm. so little difference.

It's difficult to exactly describe the letterbox flaps, but they certainly aren't smoke tight. The thin plastic one inside won't be fire resistant of course, it would just melt and probably burn. The alloy one outside has open slots at the ends and is partly why I posted about the anomoly.
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Danidl

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Agreed and understood, but two night fire wardens hired per block and equipped with mobiles and portable sirens would have been sufficient safeguard. Also the five blocks are in a group in sight of each other, so ten pairs of eyes on watch.

Not only far cheaper than using hotels but also far kinder to the residents.
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.. On reflection I want to revise my previous comment , All those high rise buildings in the UK , particularly those whose names have been published are now intrinsically much less safe than they were a fortnight ago. Careless talk costs lives, and this is a case in point where vulnerabilities should not have been published before remedies being made available. A few firewardens unfortunately won't cut it.
 

flecc

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.. On reflection I want to revise my previous comment , All those high rise buildings in the UK , particularly those whose names have been published are now intrinsically much less safe than they were a fortnight ago. Careless talk costs lives, and this is a case in point where vulnerabilities should not have been published before remedies being made available. A few firewardens unfortunately won't cut it.
Since there's been a 100% failure of the new more stringent tests, publishing the tower names hasn't made any difference in this respect. All cladded towers are potential targets now.

But I still insist fire wardens are more than adequate as a safeguard, since they not only protect against a cladding fire but all other sources of fire. In respect of Camden which was what I was posting about, we are speaking of a three week period for the cladding removal.

Where accidental cause is concerned, given that Grenfell was one cladding fire event in decades, what is the chance of a repeat nearby within a three week period? It's so vanishingly small it simply doesn't have to be considered.
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Danidl

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Since there's been a 100% failure of the new more stringent tests, publishing the tower names hasn't made any difference in this respect. All cladded towers are potential targets now.

But I still insist fire wardens are more than adequate as a safeguard, since they not only protect against a cladding fire but all other sources of fire. In respect of Camden which was what I was posting about, we are speaking of a three week period for the cladding removal.

Where accidental cause is concerned, given that Grenfell was one cladding fire event in decades, what is the chance of a repeat nearby within a three week period? It's so vanishingly small it simply doesn't have to be considered.
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.. I was not referring to accidental causes.
 
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flecc

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.. I was not referring to accidental causes.
I understood that, but still insist the fire wardens I specified would protect against a deliberate act too.

Logically residents during the cladding removal three weeks would be far safer than they would be afterwards with no fire wardens.

Just think about that three weeks:

1) First the scaffolders encasing the building.

2) The workmen there each day doing the removal.

3) The rapidly diminishing area of cladding.

4) Ten pairs of fire warden's eyes through all other times.

5) The protection against all other fire sources given by all those scaffolders, workmen's and fire warden's eyes.

It would be the safest period ever in the life of the building.
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mike killay

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Another point that will have to be explored is just what did the Fire Brigade see on arrival.
Some accounts say that they entered the flat that was on fire, extinguished the blaze and were preparing to leave before the external fire was noticed.
Obviously, in future high rise fires, the first thing they will check is the exterior cladding as well as tackling the fire.
Next, just how does this cladding burn?
i.e. does it go up like petrol soaked paper, or does it smoulder for some time unnoticed before catastrophically bursting into flame.
 

flecc

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i.e. does it go up like petrol soaked paper, or does it smoulder for some time unnoticed before catastrophically bursting into flame.
It must be very slow reacting to fire, for the simple reason that it passed all previous fire resistance tests.

The government have acknowledged today that the new tests have been deliberately been made more stringent, as I posted earlier, moving the goalposts.

The betting is that they are just applying flame for as long as it takes to get it to ignite into flame, rather than just for a specified time period which is the usual way.
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mike killay

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The betting is that they are just applying flame for as long as it takes to get it to ignite into flame, rather than just for a specified time period which is the usual way.
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Having struggled to light more than a few barbecues in my time I suspect that this foam is similar in that it does not readily ignite, but once it gets going there is little that can stop it.
 
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tillson

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It must be very slow reacting to fire, for the simple reason that it passed all previous fire resistance tests.

The government have acknowledged today that the new tests have been deliberately been made more stringent, as I posted earlier, moving the goalposts.

The betting is that they are just applying flame for as long as it takes to get it to ignite into flame, rather than just for a specified time period which is the usual way.
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The BBC are reporting this as all cladding failing fire safety tests. The implication being that this has always been the case. The truth is that this is a modified and more severe tests, conceived after the tower fire had taken place. It's misleading.
 
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Zlatan

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The problem may involve the leakage of the flammable isobutane refrigerant gas into the interior of the fridge which is then ignited by an arc, possibly from the thermostat. A similar effect could be caused by the householder storing flammable substances or aerosols with hydrocarbon propellants in the refrigerator or by using an aerosol cleaner on the interior. Hydrocarbons were almost universally adopted by manufacturers after the phase-out of CFCs in the 90s. While many in the industry preferred R134a, environmental groups and Greenpeace in particular, championed hydrocarbons as the natural alternative as they are non-ozone-depleting and non-global warming. Despite industry concerns as to its flammability, isobutane has become the standard domestic refrigerator gas and has become popular in certain plug-in commercial refrigerators. Only last month Waitrose announced that it was to use hydrocarbons in the refrigeration systems of all its new stores and refurbs. Greenpeace developed Greenfreeze technology in 1992 utilising isobutane and propane as refrigerants and cyclopentane for producing the insulating foam. According to the environmental group, the technology is currently used in over 300 million refrigerators worldwide. While these incidents involve fridges in the UK, ACR News is also investigating similar incidents in Europe and as far away as Iceland and South Africa. ACRIB said it was monitoring the situation in association with all refrigeration manufacturers.

But, would a chip pan fire had been as damaging ??
 

Croxden

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Gordon Bennet !!!
 

Woosh

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removing cladding is the wrong tactic.
There are so many 'chimneys' in any building where flames and smoke can funnel, what are we going to do? add fire barriers to all the risers?
The right tactic is to install sprinklers.
 
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Wicky

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Or learn from the Scottish...

How 1999 Scottish tower block fire led to regulation change

Following the Grenfell Tower, 60 high-rise buildings in 25 local authorities in England have failed fire safety tests so far. But no local authority or housing association tower blocks in Scotland have been found to use the same kind of cladding.

In Scotland, a change to building regulations in 2005 made it mandatory for builders to ensure that any external cladding "inhibited" fire spreading. The new regulations were introduced following a fatal fire in a Scottish tower block in 1999.
 

Danidl

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The problem may involve the leakage of the flammable isobutane refrigerant gas into the interior of the fridge which is then ignited by an arc, possibly from the thermostat. A similar effect could be caused by the householder storing flammable substances or aerosols with hydrocarbon propellants in the refrigerator or by using an aerosol cleaner on the interior. Hydrocarbons were almost universally adopted by manufacturers after the phase-out of CFCs in the 90s. While many in the industry preferred R134a, environmental groups and Greenpeace in particular, championed hydrocarbons as the natural alternative as they are non-ozone-depleting and non-global warming. Despite industry concerns as to its flammability, isobutane has become the standard domestic refrigerator gas and has become popular in certain plug-in commercial refrigerators. Only last month Waitrose announced that it was to use hydrocarbons in the refrigeration systems of all its new stores and refurbs. Greenpeace developed Greenfreeze technology in 1992 utilising isobutane and propane as refrigerants and cyclopentane for producing the insulating foam. According to the environmental group, the technology is currently used in over 300 million refrigerators worldwide. While these incidents involve fridges in the UK, ACR News is also investigating similar incidents in Europe and as far away as Iceland and South Africa. ACRIB said it was monitoring the situation in association with all refrigeration manufacturers.

But, would a chip pan fire had been as damaging ??
A well structured and considered posting, but it is not the butane or pentane in the compressor which is the significant risk but that inside the foam. I just checked the amount in my hotpoint fridge 2.5 grams and in my freezer 5 grams. There would be more in a butane lighter . There are newer compressors designed with carbon dioxide as the working fluid.
We all remember when deep frying in oil over a gas flame was the cause of multiple fires, the thermostat controlled electric modelsat low cost put an end to that practice.
 
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Zlatan

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A well structured and considered posting, but it is not the butane or pentane in the compressor which is the significant risk but that inside the foam. I just checked the amount in my hotpoint fridge 2.5 grams and in my freezer 5 grams. There would be more in a butane lighter . There are newer compressors designed with carbon dioxide as the working fluid.
We all remember when deep frying in oil over a gas flame was the cause of multiple fires, the thermostat controlled electric modelsat low cost put an end to that practice.
Thanks.
Any fire needs a source of ignition , fuel and oxygen. The isobutane provides initial fuel for fire to start with some as yet unknown ignition point.( spark)
Only after fire has started will the foam be problematic. A spark would not ignite the foam. The amount of gas is fairly irrelevant, imagine size of fire you could start with cigarette lighter. Other issue about Butane is it is heavier than air, and will congregate in base of fridge. ( I have encountered this on boats running LPG ,where propane builds up overtime inn bilges and then bilge pump clicks in, igniting the gas. This is far more of a problem than with petrol vapour.( but can happen with both)
I,m not blaming fridge but in this case it seems it transpired to line up Tillsons Swiss cheese holes, it seems to me however that almost any internal fire with any substantial amount of fuel could have triggered the turn of events.
There are plenty of substances in households which make viable fuels.
A report I read suggested designers had assumed high intensity fires ( plenty of fuel) would only be encountered on outside of building. ( ie car fire,wheelie bin etc etc) I wonder if this was flawed thinking ???
PS. I,m only assuming Isobutane is heavier than air ? Either way its dangerous to use in fridges that will eventually leak near ignition points.
 
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